A seven-year, $155 million commitment is not just big in Japan but big anywhere, and the Yankees' willingness to make that commitment to Masahiro Tanaka was the result of a perfect storm -- a feeble free-agent market, a desperate Bronx squad burned by 2013's frustrations and, yes, most of Alex Rodriguez's $25 million salary coming off the books for '14.

But while Tanaka owes an "arigatou" to all of the above, his most heartfelt thank you ought to go to Yu Darvish.

Contrary to the comparisons that naturally cropped up as Tanaka made his foray into free agency, these are two fundamentally different pitchers. If we're going to liken Tanaka to Darvish merely because they're both from Japan, we might as well mentally connect Justin Verlander and Joe Saunders because they're both from Virginia.

Place of birth really doesn't add much depth to the discussion.

What allowed Darvish to make a nearly instantaneous leap from unproven pitcher to Cy Young contender was the vast array of his arsenal, which fed off a fastball that averaged 93.5 mph last season, according to FanGraphs. Darvish also benefitted from the mixed heritage and multicultural upbringing that helped him settle somewhat seamlessly into American life.

Tanaka, on the other hand, is cut more from the cloth that gave us Daisuke Matsuzaka, Kei Igawa and Hideki Irabu. Not that he'll be anywhere near as big of a bust as those guys (he's slightly younger, for one, and we'd like to believe the scouting associated with this signing is a little more sophisticated than it was then), but he more closely fits that "traditional" Japanese mold.

In terms of stuff, a good comparable for Tanaka might be Hisashi Iwakuma, who obviously just had a monster season for the Mariners. Iwakuma averaged 90.3 mph with his fastball last season, almost precisely the same mark that Tanaka averaged in Nippon Professional Baseball (90.7, per Patrick Newman of NPB Tracker) in 2012. As Iwakuma has (and countless others have) demonstrated, you can survive and thrive with savvy and command and deception over raw stuff.

But the question of whether Tanaka will thrive at a level worthy of this kind of money over this length of time is a legitimate one.

What is unquestionable is that Tanaka wouldn't have engendered that kind of commitment if Darvish hadn't set such an incredible precedent. It was the Darvish deal made by the Rangers (a record $51.7 million posting fee to Darvish's former team, plus a $56 million guarantee to Darvish himself) that helped prompt Pirates president Frank Coonelly to speak up at an Owners' Meetings general session last November about the unfairness of the posting system, as it pertains to MLB's small-market clubs.

The posting fees, after all, were paid directly to NPB teams and, therefore, were not subject to MLB's luxury tax, and the Darvish deal demonstrated just how outlandish those fees could get for top talent in today's marketplace. Coonelly initiated the change we saw this winter, to a system in which the posting fees were limited to $20 million so that a far more substantial sum of the investment goes to the player, and, hence, is taxable.

That, of course, is how Tanaka was able to operate more like a stateside free agent and why he was able to negotiate a contract that guarantees him $99 million more than Darvish, who, again, very well might be the superior pitcher.

Free agency, like so much of life, is all about timing and context.

More to the point, it was Darvish's success in Texas that prompted the Yankees to be so willing to venture down this road again. Because, remember, they were extremely cautious and careful in their dealings with Yu. Brian Cashman still had the scars from getting burned by Igawa, and he was reluctant to take on the riverboat gambler mentality one must possess in assigning Cy Young-like dollars to a pitcher whose tangible, transitional value is so vague. The Yanks did bid on Darvish, as did most teams in MLB, but they did so half-heartedly and without any expectation that they would be finalists for his services.

Flash forward two years, and there had to be regret on the part of Cashman and Co. for that tact. Their rotation had splintered and was in clear need of repair. Already, there are questions and concerns over what the future holds for CC Sabathia, who, like so many before him, will have to learn how to do more with less, now that his velocity has declined. And certainly, there are questions about how much a 38-year-old Hiroki Kuroda has left in the tank after his fade the last two months of 2013, or what Ivan Nova and Michael Pineda can reasonably be counted on to contribute.

Tanaka, therefore, became a must-have commodity for the Yankees, who, contrary to any since-abandoned stance about staying under the luxury tax, are perpetually in win-now mode. Ironically (or, perhaps, intentionally), they wound up, between the posting fee and contract, doling out the same amount of money and years here as they had offered to star second baseman Robinson Cano earlier this winter.

This signing does not patch all the Yanks' holes. Despite a staggering $465 million in commitments this winter, they still don't have a settled infield at second and third base, and they still don't know precisely what the closer role will look like in the wake of the Mariano Rivera era.

But because of the pure optimism that arrives with Tanaka, there is a lot more reason to believe in the Yankees' ability to contend today than there was yesterday. Maybe that optimism is misguided, for there is plenty of historical precedent in play here to suggest as much, but the scouts will tell you that Tanaka does have the fastball-splitter-slider mix and the competitive mental mindset to be a success at this level. We'll soon find out if they're right and if Tanaka will present as positive an impact to the Yanks' rotation as Darvish has presented to the Rangers' rotation.

Make no mistake, though: Tanaka does not have a great deal in common with Darvish -- not in stuff and, now, not in salary.

The only relation between the two is place of birth and the "arigatou" owed from one to the other.